MediaWiki

It empowers teamwork with dynamic and productive team sites for every project team, department, and division. Share and manage content, knowledge, and applications to empower teamwork, quickly find information, and seamlessly collaborate across the organization.

The core software is built by hundreds of community volunteers, and when you’re ready for more there are thousands of plugins and themes available to transform your site into almost anything you can imagine. Over 60 million people have chosen WordPress to power the place on the web they call “home” — we’d love you to join the family.

Capture the knowledge that's too often lost in email inboxes and shared network drives in Confluence instead – where it's easy to find, use, and update.

It is a simple to use and highly versatile Open Source wiki software that doesn't require a database. It has clean and readable syntax. The ease of maintenance, backup and integration makes it an administrator's favorite. Built in access controls and authentication connectors make it especially useful in the enterprise context and the large number of plugins contributed by its vibrant community allow for a broad range of use cases beyond a traditional wiki.

Drupal is an open source content management platform powering millions of websites and applications. It’s built, used, and supported by an active and diverse community of people around the world.